Lumbar interspinous prosthesis and its applications

Abstract

A lumbar inter-spine prosthesis includes a torsion spring with two branches ( 3, 4 ) each end of which includes a fixation system ( 5 ) for attachment to the apophysis ( 1 ) of a vertebra ( 2 ).

1 - 11 . (canceled) 
   
   
       12 . A lumbar interspinous prosthesis, comprising a torsion spring, having an axis ( 0 ) and an external diameter, with two branches ( 3 ,  4 ), each end of which has a system ( 5 ), the said system having a center, for fixation to an apophysis ( 1 ) of a vertebra ( 2 ). 
   
   
       13 . The interspinous prosthesis as claimed in  claim 12 , wherein the axis ( 0 ) of the spring is offset with respect to the straight line joining the centers of the systems for fixation to the apophyses. 
   
   
       14 . The interspinous prosthesis as claimed in  claim 12 , wherein the ends of the branches ( 3 ,  4 ) of the spring are fastened to the apophyses ( 1 ) indirectly by way of a fastening component ( 5 ) which fixes itself to the apophyses ( 1 ). 
   
   
       15 . The interspinous prosthesis as claimed in  claim 14 , wherein the fastening component ( 5 ) is a clip comprising a generally flat elongate blade whose ends are curved on the same side in order to form a hook ( 6 ,  7 ) for fastening to the apophysis ( 1 ) for which it is intended. 
   
   
       16 . The interspinous prosthesis as claimed in  claim 15 , wherein the elongate blade has a Y shape in order to form two hooks ( 7 ) at one end and a single hook ( 6 ) at the other end. 
   
   
       17 . The interspinous prosthesis as claimed in  claim 15 , wherein the blade comprises two sliding parts. 
   
   
       18 . The interspinous prosthesis as claimed in  claim 12 , wherein the ends of the branches ( 3 ,  4 ) of the spring are fastened directly to the apophyses ( 1 ). 
   
   
       19 . The interspinous prosthesis as claimed in  claim 12 , wherein the ends of the branches ( 3 ,  4 ) of the spring are fastened directly to the apophyses ( 1 ) and in that the end of each branch ( 3 ,  4 ) folds back in a loop shape in order to form a hook ( 6 ). 
   
   
       20 . The interspinous prosthesis as claimed in  claim 12 , wherein the external diameter of the spring is 3 to 13 mm. 
   
   
       21 . The interspinous prosthesis as claimed in  claim 12 , characterized in that the diameter of the wire from which the spring is made is 1 to 4 mm. 
   
   
       22 . The interspinous prosthesis as claimed in  claim 12 , wherein the axis ( 0 ) of the spring, at rest, is offset with respect to the straight line joining the centers of the systems for fixation to the apophyses ( 1 ) by 4 to 16 mm. 
   
   
       23 . A method for stabilizing a lumbar articulation, wherein an interspinous lumbar prosthesis comprising a torsion spring with two branches ( 3 ,  4 ), each end of which has a system ( 5 ) for fixation to an apophysis ( 1 ) of a vertebra ( 2 ) is fitted in place between two vertebrae. 
   
   
       24 . A method of  claim 23  wherein the two vertebrae are lumbar vertebrae. 
   
   
       25 . A method of  claim 23  wherein the branches of the spring are brought together with the aid of a suitable ancillary instrument, the ends of the branches are fixed to apophyses of two adjacent vertebrae, and the branches are released. 
   
   
       26 . The interspinous prosthesis as claimed in  claim 13 , wherein the ends of the branches ( 3 ,  4 ) of the spring are fastened to the apophyses ( 1 ) indirectly by way of a fastening component ( 5 ) which fixes itself to the apophyses ( 1 ). 
   
   
       27 . The interspinous prosthesis as claimed in  claim 16 , wherein the blade comprises two sliding parts. 
   
   
       28 . The interspinous prosthesis as claimed in  claim 13 , wherein the ends of the branches ( 3 ,  4 ) of the spring are fastened directly to the apophyses ( 1 ). 
   
   
       29 . The interspinous prosthesis as claimed in  claim 13 , wherein the ends of the branches ( 3 ,  4 ) of the spring are fastened directly to the apophyses ( 1 ) and in that the end of each branch ( 3 ,  4 ) folds back in a loop shape in order to form a hook ( 6 ).